Grate mechanism



c. F. MILLER GRATE MECHANISM April 29, 1924.

Filed March 2. 1920 INVENTOR. C. F. er

' TTORNEY Fatented Apr. 29, lgz i.

ra' s r I CHARLES IF. MILLER, 01? MOORE, PENNSYLVANIA, ASSIGNQR TO TINGHOUSE ELECTRIGez MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

GRATE MECHANISM.

Application flled March 2, 1920. Serial Ito. 862,888.

To all whom it may concern:

Be it known that 1, CHARLES F. MILLER, a citizen of the United States, and a resident of Moore, in the county of Delaware and State of Pennsylvania, have made a new and useful Invention in Grate Mechanism, of which the following is a specification.

My invention relates to grate mechanism and particularly to grate mechanism used A further object is to produce an inexpensive form of grate bar which may be readily assembled in the furnace or replaced.

A- further object is to produce a grate bar which may be effectively cooled by the air passing from the wind box past the grate ars.

A further object is to produce grate bars adapted to cooperate to crush any fuel or ash falling into the air delivery passages and support it in the path of the air passing the grates so that it will be returned to the fuel bed and burned.

These and other objects which will hereinafter appear are attained by means of the grate bar construction herein described and illustrated in the accompanying drawings wherein:

Fig. 1 is a fra mental perspective view of a set of grate ars embodyin my invention, which bars are illustrated lIl transverse section.

Fi 2'is a fragmental perspective view of a mo ified arrangement of grate bars.

Fig. 3 is a fragmental perspectiveview of a grate embodying my invention, showing supports for the grate and means for reciprocating the bars.

Referring to the drawings, wherein-a plurality of bars are shown in their assembled relation, the grate bars include two forms, A and Bfthe former bein reciprocatory fuel supporting bars and t e latter being auxiliary bars which are preferably stationary and supported on the furnace frame members 18 between the movable bars. The movable bars may be reciprocated in any well known manner, as by the rock-shaft 21, driven from any convenient source of power. Each movable bar A comprises a pair of channel shaped members 3 and 4c which are joined in any suitable manner, as by the counter-sunk rivets 20, to form a hollow grate .bar having a fiat fuel supporting sur face 5.v The longitudinal edges of the bar are provided with downwardly extending flanges 5', the purpose of which will hereinafter appear. The bars A are arranged in parallel relation and are Spaced apart to 70 provide an air delivery s ace 6 between the bars through which air 1s delivered to the fuel from the wind box which is usually located beneath the bars. p

In the usual form of grate bar mechanisms, fuel and ashes, hereinafter referred to as siftings, fall through the air space between the grate bars and accumulate within the wind box from whence they must be removed at certain intervals through cleaning and inspection openings provided in the wind box. The opening of the wind box for the purpose of cleaning the sittings therefrom disturbs the air supply to the furnace and consequently interferes with the maintenance of a uniform draft.

In order to obviate this difficulty as well as to insure the complete combustion of all the fuel delivered to the grates, the auxiliary bars B are placed so as to form channel shaped members which when placed beneath the air spaces6 bet-ween bars A enitrap all siftings falling through them. Each of the bars B includes a pair of channel shaped members 7 and 8, which are joined together to form a hollow bar having a pair of upwardly extending flanges 9 which, to-

gether with the upper wall of the bar form achannel 10 into which the downwardly extending flanges 5' project so as to form a trap for retaining the siftings. The grate bars A and B are spaced apart so as to provide sinuous passages 11 between the ars through which air passes from the wind box to the air passages 6 between the barsA. It will be seen that the auxiliary bars B serve to support siftings falling through the air passages, directly in the path of the air blast flowing through the air passages 11. The

relative movement of the bars A and B causes the siftings to be crushed between them into fine particles which are conducted by the air current along the channel 10 to a point therein where the air is passing freely through the passage 6. Here they are carried upward and into the fuel bed again,

where any particles of unburned fuel, such as coal or coke may be consumed. In this manner the channel 10 is constantly cleared of siftings and, as a result, the passage 6 is maintained in open condition throughout its entire length, thereby ensuring a uniform distribution of air throughout the entire grate area. It will be seen that this form ofgrate construction results in both a saving -in fuel and labor.

. sequently, the bars are maintained at a safe operating temperature and the air delivered to the furnace is heated by contacting with the bars prior to entering the fuel bed.

The bar sections forming either form of bar are identical and interchangeable. The castings are simple and inexpensive to make and may be replaced with a minimum of disturbance to the remaining bars.

In Fig. 2, I have shown a modified arrangement of bars which may be used instead of the hollow bars illustrated in Fig. 1. The lower bar comprises a channel shaped portion 12 having adepending centrally disposed flange 13. The flange serves both as a reinforcement to the channel member to prevent warping and as a heat conducting surface adapted to contact with the air flowing from the wind box to the fuel bed. 'A set of upper bars 15 having reinforcing ribs 14 and flanges 16 cooperate with the lower set of. bars, the flanges 16 fitting within the channel portions 12, adjacent flanges being spaced Suficiently to provide air channels, the flanges 12 and 16 and the ribs 14 cooperating to constitute tortuous air assages.

While I have descri ed and illustrated two embodiments of my invention, it will be apparent to those skilled in the art that various changes, modifications, additions and omissions may be made in the apparatus described and illustrated without departing from the spirit and scope of the invention as set forth by the appended claims.

What ll claim is:

1. A furnace comprising a grate surface provided with upwardly opening air passages and chambers adapted to receive siftings falling through the passages and supmoved through the said passageto the furnace by air passing upwardly into the furnace.

3. The combination with a furnace grate having an air passage opening upwardly into the furnace, of a member provided with a trough disposed beneath the passage for receiving siftings falling through the said passage and supporting them in the path of air flowing through the trou h to the air passage so that they may e moved through the said passage to the furnace by air passin upwardly into the furnace, and means or crushing the siftings falling into the said trough.

4:. A furnace grate comprising a plurality of bars spaced apart to form an air passage therebetween and provided at the adjacent edges with downwardly directed flanges, and a channel member beneath the airpassage adapted to receive the sittings and to form with the said flanges an a1r passage communicating with the first air passage and the air supply of the furnace.

sages therebetween, and a channel member beneath the space between the bars adapted furnace grate comprising a phi-- rality of bars spaced apart to form air paswardly through the space between the bars, i

the said bars being provided with downwardly directed flanges extending into the said channel member and'spaced from the bottom of the channel therein, whereby an air passage is formed between the flange and the channel member.

6. A furnace grate comprising a plurality of grate bars each having a hollow body por tion and a top portionof greater width. than the body portion provided at'the edges with downwardly extending flanges, the said bars being spaced apart to form an air passage between said flange, and a plurality of hollow bars disposed between the body 'ortions of the first bars, each provided wit a depression in the upper side thereof adaptedto receive the flanges of the first bars and form therebetween air passages communicating with the first air passage and the air supply of the furnace.

7. A furnace comprising a plurality of movable grate bars each having a body portion and a fuel supporting portion provided at its edges with downwardly directed flanges, the said bars being spaced apart to form an air passage between them, and a stationary member provided with a trough adapted to receive the flanges of the movable bars and support the sittings falling through the grate in the path of the air flowing to the said passage.

8. A furnace comprising a plurality of movable grate bars each having a body portion and a fuelsupporting portion provided at its edges with downwardly directed flanges, the said bars being spaced apart to form an air passage between them,-

and a stationary member provided with a trough adapted to receive the flanges of the movable bars and support the siftings falling through the grate in the path of the air flowing to the said passage, the flanges of said bars and the trough of said stationary memher being so constructed and disposed with relation to each other as to effect a crushing of the sittings in the trough upon movement of the bars.

In testimony whereof, I have hereunto subscribed my name this twenty-sixth day of February, 1920.

CHARLES F. MILLER. 

